About 5 seconds. 1 to add them with NEI, 4 to equip. Including the search time, it was about 10 seconds. Back in 1.2.5, anyway. Now it's over a minute.
But for real, ETA: 2 Forevers. I don't want a quantum suit anymore. Honestly, I found them somewhat cheap.(not as in not pricey, but as in OP) It feeds you, protects you from all status effects, holds massive amounts of power and uses it slow enough that it takes a ton of actual fighting to drain, and is basically a Obsidian Armor in of that wearing a full suit makes you invincible when facing foes which don't do suffocation damage.
Plus it does all this and more.
No thanks, I think my Enchanted Thaumium armor is fine. I might try to get a Nanosaber with Vorpal V something else sometime, but not yet.